Multi-element pens, in the general sense, are not new. Many a school child has found fascination in multi-colored ball point pens, which give them a capacity to express themselves with a new-found versatility and artistic flair in their writings and drawings. Ball point pens also serve the cause of neatness in that they encapsulate their ink reservoirs within cartridges comprising a hard plastic or metal element case and a cap over the end of the case having a tight-fitting ball point writing end. Ink cannot leak from the cartridge unless the ball is rolling along a surface, preferably a suitable writing surface. To accommodate the needs of those seeking colorful expression and cleanliness in the form of multi-element ball point pens, the prior art has responded by providing a plethora of alternative structures for such pens.
For instance, French Patent no. 1,307,761, which issued on Sep. 17, 1962 to Dutoit, is directed to a multi-element pen having a plurality of ball point cartridges therein, presumably giving the pen the ability to accommodate multiple colors, and a mechanism for selectively extending one of the pen cartridges to thereby allow the pen to write in a selected color.
Another such pen is described in U.S. Pat. No. 2,468,258, which issued on Apr. 26, 1949, to Fahringer et al., and which is directed to plotting instruments of the type known as ball point pens. Specifically, Fahringer et al. provide a structure which allows removal and replacement of individual ball point pen cartridges, allowing the pen to be reloaded as individual cartridges become spent. Fahringer et al. also teach that any ball point pen cartridge may be replaced by a cartridge containing pencil lead to enable the pen to also selectively function as a pencil.
In yet another example, U.S. Pat. No. 3,103,205, which issued on Sep. 10, 1963 to Lagnani, is directed to a multiple-element and of a type similar to that disclosed in Fahringer et al., above. Namely, Lagnani provides for a pen body capable of receiving ball point cartridges which can be reloaded should an individual cartridge become empty.
Unfortunately, school children grow older; and as they progress into high school, college and career, their needs for writing instruments change. Instead of ball point pens, many adults prefer the advantages provided by felt tip pens, wherein wicking-type elements are employed within the pens to hold ink within a fibrous matrix. In contrast with ball point pens, felt tip pens provide a capacity to express one's self in bolder, more colorful strokes, but nonetheless allow the same degree of control over placement of those strokes. This is due to provision of a relatively small writing point on the end of the wick which has an accuracy of delivery similar to ball points. Of course, such writing points can be made of almost any size to produce lines widths from the very fine to the very broad. Although felt tip pens are more prone to accidental leakage caused by unintentional contact of the writing point with another object, adults tend to take greater care in handling pens than do children.
Another favorite writing tool for those adults is the highlighter, a phenomenon which has arisen in the past two decades to revolutionize the process of emphasizing text. Before highlighters, one wishing to emphasize text would underscore the text with colored ink delivered from a standard ball point or felt tip pen. One could not, however, score through the text, because the ink would cover up the text, lessening its readability. Highlighters, like other types of felt-tipped pens, come in a variety of colors, allowing one to highlight text in many different colors representing a code used by the reader, each color signifying a different category or purpose, or perhaps only for aesthetic effect.
A highlighter employs a relatively large writing point in conjunction with a translucent ink to allow one to deposit the ink on a writing surface, the ink allowing previously written underlying text to remain readable. However, addition of the translucent ink calls attention to that underlying text. Highlighters share the disadvantages of other wicking-type pens in that they employ a fibrous wick which can leak.
Traditionally, both felt tip and highlighter pens have been provided only as single element pens. In the past, should a reader desire multiple highlighter colors, he had to purchase a plurality of separate, single-element highlighter pens and manage each of them separately, replacing caps and trading pens whenever necessary. Thus, one wishing to write or highlight in multiple colors had to deal with a separate pen for each color, unable to enjoy the advantages a single multi-element pen brings.
All of the devices described above are directed to multi-element ball point pens or pencils. What the prior art fails to teach is provision of a multi-element writing instrument which has been specially adapted to handle wicking-type writing elements (either felt tip or highlighter).
Because the structures previously discussed had only to accommodate ball point elements or pencil leads, they did not have to deal with the unique problems encountered when working with wicking-type elements. First, the prior art employed devices for axially displacing a particular selected element into a writing position and retracting the selected element from the writing position to a retracted position within the pen. To accomplish this displacement, the devices were located at an end of the pen distal from a writing end to force the elements, against a spring force, downward and through an opening in the writing end of the pen.
During writing, pressure applied to the writing end of the element as it wrote had to be transmitted up the element and to the device. Unfortunately, wicking elements do not have a hard plastic or metal element case by which to transmit this force. Wicking elements comprise a fibrous material within which ink is stored in a capillary fashion. Therefore, such wicking elements are not suited to receive longitudinal pressure; they simply bend or compress, frequently unleashing their ink in the process. Accordingly, the prior art provided single-element wicking pens having a structure which holds the wick at the bottom, close to the writing end, allowing the remainder of the wick to reside within the pen body without forces thereon. This arrangement is not suitable in the environment of multi-element pens, where such a structure would be too large and complex to place at the writing end of the pen.
Secondly, ball point pens are capsules. That is, they 1) form a reservoir within the element body for holding the ink and 2) cap that reservoir with a rolling ball element which, when not rolling, keeps ink from flowing from within the pen. Therefore, it is easier to control the dispensing of ink from a ball point pen than it is from a felt tip pen or highlighter.
Multi-element highlighter pens or, in general, multi-element felt tip pens were simply not available in the prior art. This was so because the prior art had not devised a way to deal successfully with the ink control and "flimsy wick" aspects of felt tip elements. Therefore, the prior art has utterly failed in its attempts to provide a multi-element felt tip pen, especially of the highlighter variety, which combines the advantages of multi-element ball point pens with those of felt tip or highlighter pens.